Preferred Language
Articles
/
joe-1553
Numerical Investigation of Aerodynamic Characteristics of Supercritical RAE2822 Airfoil with Gurney Flap
...Show More Authors

Gurney flap (GF) is well-known as one of the most attractive plain flaps because of the simple configuration and effectiveness in improving the lift of the airfoil. Many studies were conducted, but the effects of GF on the various airfoil types need to be further investigated. This study aimed to clarify the effect of GF in the case of the supercritical airfoil RAE2822. This research includes a steady, two-dimensional computational investigation carried out on the supercritical airfoil type RAE-2822 to analyze Gurney flap (GF) effects on the aerodynamic characteristics of this type of airfoil utilizing the Spalart-Allmaras turbulence model within the commercial software Fluent. The airfoil with the Gurney flap was analyzed for three different height values 1%c, 2%c, and 3%c, and five mounting angles (30°,45°,60°,75°, and 90°) with the axial chord for angles of attack (-1°,-2°,-3°,0°,1°,2°,3°). The calculations showed that when GF height is increased, the maximum suction pressure on the upper surface increases by 25.4%, 36.5%, and 68.83% when the height of the Gurney flap is 1%c, 2%c, and 3%c, respectively, compared with that on the airfoil without GF. The lift coefficient was also increased, and the shock waves moved downward by increasing GF height. As Gurney flap heights increase, the drag coefficient increases gradually for positive angles of attack but for negative angles of attack. The drag coefficient also decreases with increasing the GF heights. As long as the angle of the mounting is between 45o and 90o, the lift coefficient does not differ on a large scale. For mounting angles less than 45o, the lift coefficient drops quite fast. As a result, reducing the Gurney flap’s lift enhancement and the drag coefficient increases gradually for positive angles of attack, but for negative angles, it can be noted that the drag coefficient decreases with increasing the mounting angles of GF. The calculated values of the lift and drag coefficients with an attack angle and pressure coefficient compared with the experimental values, and a good agreement was noticed. 

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jan 07 2022
Journal Name
Iraqi Journal Of Laser
Influence of Fractional CO2 Laser Irradiation on Temperature Elevation and Bonding Strength of Resin Cement to the Zirconia Ceramic
...Show More Authors

Abstract: Objectives: To investigate the effect of temperature elevation on the bonding strength of resin cement to the zirconia ceramic using fractional CO2 laser. Background: Fractional CO2 laser is an effective surface treatment of zirconia ceramic, as it increases the bonding strength of zirconia to resin cement. Methods: Thirty sintered zirconia discs (10 mm diameter, 2 mm thickness) were prepared and divided to three groups (N=10) and five diffident pulse durations were used in each group (0.1, 0.5, 1, 5 and 10 ms). Group A was treated with 10 W power setting, group B with 20 W and group C with 30 W. During laser irradiation, temperature elevation measurement was recorded for each specimen. Luting cement was bonded to the treated z

... Show More
View Publication Preview PDF
Publication Date
Thu Oct 01 2020
Journal Name
Journal Of Engineering
Using a novel approach to determine the pore pressure of West Qurna 15 oil well in South of Iraq
...Show More Authors

Pore pressure means the pressure of the fluid filling the pore space of formations. When pore pressure is higher than hydrostatic pressure, it is named abnormal pore pressure or overpressure. When abnormal pressure occurred leads to many severe problems such as well kick, blowout during the drilling, then, prediction of this pressure is crucially essential to reduce cost and to avoid drilling problems that happened during drilling when this pressure occurred. The purpose of this paper is the determination of pore pressure in all layers, including the three formations (Yamama, Suliay, and Gotnia) in a deep exploration oil well in West Qurna field specifically well no. WQ-15 in the south of Iraq. In this study, a new appro

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Affect of learning the bag in the acquisition of historical concepts for students in the fifth grade literary history
...Show More Authors

The  adopted method in the teaching of history is conservation and indoctrination in all grades, and this will lead to a lack of students interact with teachers in the course of the lesson, and poor use of teachers to questions that raise students' thinking during the lesson, which leads to a lack of interest in the topic of the lesson and wasting opportunities contribution making it the teacher at the center of the educational process, and to provide arrogating the researcher to contribute to teaching style with the belief that the use of this method of teaching could lead to overcome the difficulties and problems faced by the teaching material.

And there are educational complexes integrated approac

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
The Effect of Annealing on The Structural and Optical Properties of Copper Oxide Thin Films Prepared by SILAR Method
...Show More Authors

Copper oxide thin films were deposited on glass substrate using Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The thickness of the thin films was around 0.43?m.Copper oxide thin films were annealed in air at (200, 300 and 400°C for 45min.The film structure properties were characterized by x-ray diffraction (XRD). XRD patterns indicated the presence of polycrystalline CuO. The average grain size is calculated from the X-rays pattern, it is found that the grain size increased with increasing annealing temperature. Optical transmitter microscope (OTM) and atomic force microscope (AFM) was also used. Direct band gap values of 2.2 eV for an annealed sample and (2, 1.5, 1.4) eV at 200, 300,400oC respect

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Jan 02 2021
Journal Name
Journal Of The College Of Languages (jcl)
Semantics of the Russian Verbs of Destruction in Contemporary Linguistics: Семантический Анализ Глаголов Деструкции Русского Языка В Современной Лингвистике
...Show More Authors

The article states that the Russian verbs of destruction belong to the lexical-semantic group of physical impact. They include verbs with the meaning of “damage” and “destroy”. It is emphasized that each of these groups is relatively independent; the cut line between them is fuzzy and arbitrary. It is postulated that when the object is completely destroyed, then the verb has the meaning of “destruction”,  and when the object is partially destroyed, then the  verb has the meaning of “damage”. It is this feature that individualizes the meaning of verbs. The study distinguishes between the groups and the nature of the object as- animate / inanimate. The object of the action of the “destruction” can only be inan

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
Comparative Study in Attitudes towards the Covid-19 Vaccine According to Locus of Control (Internal - External) of University Students
...Show More Authors

Abstract

The current research aims to identify the attitudes towards the Covid-19 vaccine and the Locus of Control (internal, external) among university students, to identify the significance of the difference in attitudes towards the Covid-19 vaccine, the significance of the difference in the Locus of Control (internal, external) according to the gender variable (male, female), and to identify the significance of the difference in students’ attitudes towards Covid-19 vaccine according to the Locus of Control (internal, external). To achieve the objective of the research, the researcher developed two scales, a scale of (20) items to identify the attitudes toward a covid-19 vaccine, and a scale of the locus of c

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 15 2020
Journal Name
Al-academy
The effect of the Iraqi marshes environment on the works of artist Mahoud Ahmed: محمود حسين عبد الرحمن حسين
...Show More Authors

Scientific research on the environment of the Iraqi marshes, its beauty and its characteristics is considered one of the most important functions of Iraqi universities and scientific institutions, because of its great historical impact related to the identity of Iraq and the Iraqis and the basis of science and science, through which the first letter and the first human civilizations were established and in the same importance technical research is among the most important functions of departments Institutes and colleges of the arts, research centers and museums inside and outside Iraq. Also, research centers specialized in the natural environment of Iraq, including the marshes. Therefore, it is hoped that this research will develop the a

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jan 01 2021
Journal Name
Indian Journal Of Forensic Medicine & Toxicology
Evaluation of Morphological (Macroscopic and Microscopic) Parameters of Placentas in Pregnancies Complicated by Preeclampsia, Diabetes and Preeclampsia and Diabetes.
...Show More Authors

This study was done to compare the morphometric parameters of placentas in well controlled patients with preeclampsia, diabetes, and preeclampsia-diabetes with that of normal uncomplicated placentas. Patients & Methods: A total of Twenty four placentas were freshly collected. Six placentas for control group and eighteen placentas for complicated group (preeclamptic-diabetic and preeclamptic--diabetic subgroups). The placentas were grossly examined (shape, number of cotyledons, weight, and thickness). After suitable fixation, tissue processing and sectioning, the sections were stained by hematoxylin and eosin to study the general morphology and morphometry of the following parameters: number of terminal villi, number of syncytial knots, numb

... Show More
Publication Date
Wed Apr 04 2012
Journal Name
The Iraqi Journal Of Veterinary Medicine
Toxicopathological study of aqueous extract of beetle cocoon Larinus maculatus F. on some internal organs in male albino mice
...Show More Authors

The present study was carried out to investigate the effect of oral administration of hot aqueous extract of beetle cocoon Larinus maculatus Faldermann, in a two doses 50 and100mg/Kg/Bw for 25 and 45days respect- tively on some organs such as liver, lung, kidney, intestine, heart, spleen, and brain in male mice Mus musculus. The results indicated that there were toxicopathological changes in many tissues of experimental animals. Histo -pathological changes was dose and period dependent . It was found that the aqueous extract of beetle cocoon has undesirable effect at the administered doses, since the raw extract of this cocoon is currently being used in Folk medicine as treatment for cough, bronchitis in Iraq. This study revealed that the l

... Show More
Preview PDF
Crossref
Publication Date
Tue Feb 01 2022
Journal Name
Current Pharmaceutical Analysis
Analytical Methods for the Identification of Pigments in Tattoo Inks and Some of Their Physiological Side Effects: A Review
...Show More Authors

In this review, numerous analytical methods to distinguish pigments in tattoo, paint, and ink items are discussed. The selection of a method was dependent upon the purpose, e.g., quantification or identification of pigments. The introductory part of this review focuses on describing the importance of setting up a pigment-associated safety profile. The formation of different degradation chemical substances as well as impurity trends can be indicated through the chemical investigation of pigments in tattoo products. It is noteworthy that pigment recognition in tattoo inks can work as a preliminary method to identify the pigments in a patient's tattoo before being removed by laser therapy. Contrary to the stud

... Show More
View Publication
Scopus (2)
Crossref (2)
Scopus Clarivate Crossref